Hi all -
I've found some valuable insight and tips searching this forum before joining today as I worked down a 'cranks - no start' issue in my son's 2004 Impala so THANK YOU to all the enthusiasts and posters who unknowingly helped me work this problem.
I've have come to believe that the PCM is faulty. So, I joined the forum today to pose a question about replacement PCM options. Looking for advice on best place to source one. F1S (Flagship 1) popped up in my searches and $139 programmed to the car with free shipping seems like a heck of a deal. They have some good reviews and some horrific ones. Not sure if anyone has had any experience with them.
I do have access to a Tech 2 if I decide to go with a rebuilder or a reman.
To put some meat on the bone, here is some of what I've done/tested:
So that's where I'm at. Looking for replacement PCM options. We have some highly recommended sources for the Euro vehicles I've been involved with for the past decade but I'm looking for the Impala experts for some guidance here.
Thank you in advance....
I've found some valuable insight and tips searching this forum before joining today as I worked down a 'cranks - no start' issue in my son's 2004 Impala so THANK YOU to all the enthusiasts and posters who unknowingly helped me work this problem.
I've have come to believe that the PCM is faulty. So, I joined the forum today to pose a question about replacement PCM options. Looking for advice on best place to source one. F1S (Flagship 1) popped up in my searches and $139 programmed to the car with free shipping seems like a heck of a deal. They have some good reviews and some horrific ones. Not sure if anyone has had any experience with them.
I do have access to a Tech 2 if I decide to go with a rebuilder or a reman.
To put some meat on the bone, here is some of what I've done/tested:
- cam sensor signal at the ICM = 6.xxV and cuts to 0V once in two crank revolutions (car did have a 1x crank pos sensor fault so I did fit a new one just as a precaution - this was the ONLY code present when the issue first occurred)
- crank sensor signal at the ICM (3x and 18x) = can read the breaks on both sides
- all grounds including the 3 of the 4 grounds from PCM (56 , 57, 60). none had a voltage drop of more than .002V.
- I can't really get to 16 but with no other issues I'm assuming it's good. I'm going to pull the PCM back out tomorrow and see if I can 100% rule that ground out as an issue.
- I'm also assuming the common splice is good since I'm doing a voltage drop across it for the 3 PCM grounds I did test.
- cleaned all ground connections (all were good with no corrosion)
- FP at key on approx 60psi. (pump does initial 5 sec run at key on)
- ICM power and ground is in spec
- spark is present at all 6 cylinders
- power is present at all 6 injectors with key on
- no noid light when cranking
- ground the injector connector with key on (using a bypass to B-) and noid light will light
- engine RPM can be read with scan tool when cranking
- security light is not flashing. I believe passlock disables cranking if failing but I've read both scenarios in my search of how this works. (ie...the old VATS system on our '89 Corvette would behave that way...no crank when it intervened as that system was failing before replacing the VATs module).
- all fuses are good
So that's where I'm at. Looking for replacement PCM options. We have some highly recommended sources for the Euro vehicles I've been involved with for the past decade but I'm looking for the Impala experts for some guidance here.
Thank you in advance....